NSC LM4880MX, LM4880N Datasheet

LM4880

Dual 250 mW Audio Power Amplifier with Shutdown
Mode

General Description

The LM4880 is a dual audio power amplifier capable of deliv­ering typically 250 mW per channel of continuous average
power to an 8Ω load with 0.1%(THD) using a 5V power sup­ply.

Boomer audio power amplifiers were designed specifically to
provide high quality output power with a minimal amount of
external components using surface mount packaging.

Since the LM4880 does not require bootstrap capacitors or
snubber networks, it is optimally suited for low-power por­table systems.

The LM4880 features an externally controlled, low-power
consumption shutdown mode, as well as an internal thermal
shutdown protection mechanism.

The unity-gain stable LM4880 can be configured by external
gain-setting resistors.

Key Specifications

n THD at 1 kHz at 200 mW continuous average output

power into 8Ω: 0.1%(max)

n THD at 1 kHz at 85 mW continuous average output

power into 32Ω: 0.1%(typ)

n Output power at 10%THD+Nat1kHzinto 8Ω:

325 mW (typ)

n Shutdown Current: 0.7 µA (typ)

Features

n No bootstrap capacitors or snubber circuits are

necessary

n Small Outline (SO) and DIP packaging
n Unity-gain stable
n External gain configuration capability

Applications

n Headphone Amplifier
n Personal Computers
n CD-ROM Players

Typical Application

Boomer®is a registered trademarkof National Semiconductor Corporation.

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*

Refer to the Application Information section for information concerning proper selection of the input and output coupling capacitors.

FIGURE 1. Typical Audio Amplifier Application Circuit

November 1995

LM4880 Boomer Audio Power Amplifier Series Dual 250 mW Audio Power Amplifier with

Shutdown Mode

© 1999 National Semiconductor Corporation DS012343 www.national.com

Connection Diagram

Small Outline and

DIP Packages

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Top View

Order Number LM4880M or LM4880N

See NS Package Number M08A for SO

or NS Package Number N08E for DIP

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Absolute Maximum Ratings (Note 2)

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.

Supply Voltage 6.0V
Storage Temperature −65˚C to +150˚C
Input Voltage −0.3V to V

DD

+ 0.3V
Power Dissipation (Note 3) Internally limited
ESD Susceptibility (Note 4) 3500V
ESD Susceptibility (Note 5) 250V
Junction Temperature 150˚C
Soldering Information

Small Outline Package

Vapor Phase (60 sec.)
Infrared (15 sec.)

215˚C
220˚C

See AN-450 “Surface Mounting and their Effects on
Product Reliability” for other methods of soldering surface
mount devices.

Thermal Resistance

θ

JC

(DIP) 37˚C/W

θ

JA

(DIP) 107˚C/W

θ

JC

(SO) 35˚C/W

θ

JA

(SO) 170˚C/W

Operating Ratings

Temperature Range

T

MIN≤TA≤TMAX

−40˚C≤TA≤+85˚C

Supply Voltage 2.7V≤V

DD

≤5.5V

Electrical Characteristics (Notes 1, 2)

The following specifications apply for V

DD

=

5V unless otherwise specified. Limits apply for T

A

=

25˚C.

Symbol Parameter Conditions LM4880 Units

(Limits)

Typical Limit

(Note 6) (Note 7)

V

DD

Supply Voltage 2.7 V (min)

5.5 V (max)

I

DD

Quiescent Power Supply Current V

IN

=

0V, I

O

=

0A 3.6 6.0 mA

(max)

I

SD

Shutdown Current V

PIN5

=

V

DD

0.7 5 µA
(max)

V

OS

Output Offset Voltage V

IN

=

0V 5 50 mV

(max)

P

O

Output Power THD=0.1%(max); f=1 kHz;

R

L

=

8Ω 250 200 mW

(min)

R

L

=

32Ω 85 mW
THD+N=10%;f=1 kHz
R

L

=

8Ω 325 mW
R

L

=

32Ω 110 mW

THD+N Total Harmonic Distortion+Noise R

L

=

8Ω,P

O

=

200 mW; 0.03

%

R

L

=

32Ω,P

O

=

75 mW; 0.02

%

f=1 kHz

PSRR Power Supply Rejection Ratio C

B

=

1.0 µF,

V

RIPPLE

=

200 mVrms, f=100 Hz

50 dB

Note 1: All voltages are measured with respect to the ground pin, unless otherwise specified.
Note 2: Absolute Maximum Ratings indicate limits beyond which damage may occur. Operating Ratings indicate conditions for which the device is functional, but do

not guarantee specific performance limits. Electrical Characteristics state DC and AC electrical specifications under particular test conditions which guarantee specific
performance limits. This assumes that the device is within the Operating Ratings. Specifications are not guaranteed for parameters where no limit is given, however,
the typical value is a good indication of device performance.

Note 3: The maximum power dissipation must be derated at elevated temperatures and is dictated by T

JMAX

, θJA, and the ambient temperature TA. The maximum

allowable power dissipation is P

DMAX

=

(T

JMAX−TA

)/θJAor the number given in the Absolute Maximum Ratings, whichever is lower. For the LM4880, T

JMAX

=

150˚C,

and the typical junction-to-ambient thermal resistance is 170˚C/W for package M08A and 107˚C/W for package N08E.

Note 4: Human body model, 100 pF discharged through a 1.5 kΩ resistor.
Note 5: Machine model, 220 pF–240 pF discharged through all pins.
Note 6: Typicals are measured at 25˚C and represent the parametric norm.
Note 7: Limits are guaranteed to National’s AOQL (Average Outgoing Quality Level).

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Automatic Shutdown Circuit

Automatic Switching Circuit

External Components Description

(

Figure 1

)

Components Functional Description

1. R

i

Inverting input resistance which sets the closed-loop gain in conjunction with RF. This resistor
also forms a high pass filter with C

i

at f

c

=

1/(2πR

iCi

).

2. C

i

Input coupling capacitor which blocks the DC voltage at the amplifier’s input terminals. Also
creates a high pass filter with R

i

at f

c

=

1/(2πR

iCi

). Refer to the section, Proper Selection of

External Components, for an explanation of how to determine the value of C

i

.

3. R

F

Feedback resistance which sets closed-loop gain in conjunction with Ri.

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FIGURE 2. Automatic Shutdown Circuit

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FIGURE 3. Automatic Switching Circuit

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